You've all probably heard of cat hoarding -- that variant of animal hoarding suffered by Crazy Cat Ladies the world over (like this Cat Lady in Siberia, who feeds 130 in her home every day). According to the Hoarding of Animals Research Consortium (yes, really), crazy cat ladies and their obsessive ilk collectively hoard some 250,000 animals at any given time in the United States. Not only do the attendant smells and noises bug neighbors, but the inability for most hoarders to properly care for all their animals is a serious animal welfare issue.

Well, forget about cat hoarding for the moment, and consider this. The West side of Los Angeles has an even more dire problem: rat hoarding. Specifically by two elderly, never-married twin sisters, animal lovers who, as they grew too old to care for the dogs and larger animals they once took in off the streets, moved on to caring for the rats that appeared on their property. And these women don't live in the Bronx or somewhere you might not be surprised to hear was rat-infested; they live in the tony LA suburb of Pacific Palisades. (There are tee-shirts sold here which read "If you're rich, you live in Beverly Hills; if you're famous, you live in Malibu; and if you're lucky, you live in Pacific Palisades." Which kind of sums it up.) But when a young couple and their baby moved in next door to the twin rat-hoarders a few years ago, they uncovered a dark secret that may be responsible for the wealthy side of LA's recent rat boom. The LA Weekly ran a great, horrifying story about it a few weeks ago; what follows are some of the juiciest excerpts.

The number of wild rats the Barthel sisters bred in one year— if they began with a single male and a single female — is, by the association's calculations, 2,258. That number of rats would be capable of devouring 10,931 pounds of food and excreting 56,400 rat droppings. But the sisters fed the rats for much longer than a year. They did so from the time they returned from Santa Ynez in 2002 until late 2007 — not to mention possible rat-feeding during the decades that Margaret continued teaching in Redondo to support their refuge in Santa Ynez.

Theoretically, during a second year, 2,258 rats in the Palisades could grow "a thousand-fold," to more than two million rats, says Greg Baumann of the association. That's only a mathematical figure, because the food needed to sustain two million rats would be impossibly huge, and cats were in the area. But, estimating conservatively, the two sisters added tens of thousands of rats to L.A.'s tony Westside. And perhaps far, far more.

Trouble was, even when the neighbors discovered what had happened -- and that the previous owner knew of but hadn't disclosed the problem to them (lawsuit!) -- they could never get the city to do anything about it. The sisters refused to come to the door for inspectors, and despite being by most accounts pretty crazy, had hired a savvy lawyer to help them out. They seemed untouchable; the city seemed apathetic. Finally, the neighbors threatened publicity, and the sisters caved. They agreed to let exterminators come in and take care of the rat problem in their house, fomented by their shopping-cart's-worth-of-dog-food weekly feeding regimen.

A crew wearing facemasks and hazmat suits emerged pale-faced and sober, as if they had just witnessed the aftermath of a biohazard spill — which, in a way, they had. Scott Denham says they hauled several large garbage bags heavy with dead rats from the bedrooms, kitchen, attic, basement and guesthouse, as the Denhams took photos.

But the story's not quite over yet -- it gets weirder.

Apparently, spawning a massive rat population on L.A.'s Westside doesn't disqualify homeowners'-insurance policies with State Farm. State Farm is bankrolling the Barthels' legal defense, setting in motion preparations for a bizarre yet entertaining trial, probably this year. Attempts by the two sides to reach a settlement were stymied by the Barthels' unnerving request: The Denhams would have to withdraw their demand for a permanent injunction — whose only stipulation is that the sisters not harbor rats.

"Since 1958, we've had rats," Marjorie told Barak Lurie during her deposition in May. "I've lived with rats since 1958, honey.... When I got the house in [1958], that's the day I started feeding all the animals. And I fed them as long as I lived there."

You can read the whole story here, and see video taken by the neighbors of rats running rampant here: